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| #1194208 (Received by flhurricane at: 5:09 AM 17.Aug.2024) TCDAT5 Hurricane Ernesto Discussion Number 23 NWS National Hurricane Center Miami FL AL052024 500 AM AST Sat Aug 17 2024 Satellite and surface observations indicate that the center of Ernesto made landfall on the western side of Bermuda at about 430 AM AST, with the National Museum of Bermuda recently reporting light winds and a central pressure of 972 mb. The system overall has become less organized as drier air has infiltrated much of the circulation`s southern semicircle. Earlier aircraft reconnaissance data supported 75-80 kt as an initial intensity, and with the degradation in the satellite imagery, 75 kt is chosen as the current intensity (and operational landfall intensity). The Air Force Hurricane Hunters should be out again in a few hours to sample the cyclone. While the current moderate shear is forecast to weaken today, it will take some time for the vortex to recover from the dry air as it moves across warm waters north of Bermuda. Thus little change in intensity is anticipated in the short term, and re-strengthening could begin tomorrow. This should be a fairly short-lived window, however, since Ernesto will be crossing the north wall of the Gulf Stream on Monday while moving into a strong wind shear environment. Therefore, steady weakening is forecast for the work week, and Ernesto is expected to complete extratropical transition near or just east of Newfoundland. The NHC intensity forecast is largely an update of the previous one, a bit lower in the short-term to account for recent guidance. Ernesto has turned more to the north-northeast overnight and slowed down to about 8 kt. The motion should creep in that direction today as the hurricane is stuck in an area of lighter steering currents, waiting for the next trough to move off the U.S. East coast. This slow motion and Ernesto`s large size will cause a long duration of impacts through tonight on Bermuda. The trough should force the cyclone to accelerate northeastward later in the weekend and early next week, taking Ernesto near Newfoundland Monday night. The guidance is again slower than the previous cycle, so the NHC track forecast is trended in that direction. Global model fields depict that Ernesto should open into a trough, or become absorbed in a larger polar low by 120 h over the northern Atlantic ocean, thus the NHC forecast now shows the system dissipated at that time. Key Messages: 1. Ernesto is expected to bring periods of strong winds, storm surge and battering waves on Bermuda through tonight. A hurricane warning is in effect for the island, and residents there should listen to orders from local officials. 2. Heavy rainfall from Ernesto will continue to impact Bermuda through tonight and will likely result in considerable life- threatening flash flooding, especially in low-lying areas on the island. 3. Even though Ernesto is forecast to remain well offshore the U.S. East Coast, swells generated by the hurricane are expected to affect the area through the weekend. Beach goers should be aware of a significant risk of life-threatening surf and rip currents, and stay out of the water if advised by lifeguards. Surf and rip currents are also possible on the Bahamas, Bermuda, and Atlantic Canada during the next few days. 4. Interests in Atlantic Canada should monitor the progress of Ernesto. FORECAST POSITIONS AND MAX WINDS INIT 17/0900Z 32.3N 64.8W 75 KT 85 MPH 12H 17/1800Z 33.3N 64.4W 70 KT 80 MPH 24H 18/0600Z 34.6N 63.9W 70 KT 80 MPH 36H 18/1800Z 36.6N 62.9W 75 KT 85 MPH 48H 19/0600Z 39.8N 61.2W 80 KT 90 MPH 60H 19/1800Z 43.5N 57.5W 70 KT 80 MPH 72H 20/0600Z 47.0N 51.5W 60 KT 70 MPH...POST-TROPICAL 96H 21/0600Z 51.5N 32.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 22/0600Z...DISSIPATED $$ Forecaster Blake |
